The knowledge and processes involved in accounting for water resource availability continues to benefit from new insights, knowledge and data. The Water research Commission has been very instrumental in providing support and a platform for water practitioners to take part in regular research to develop water resource assessment techniques, collate the data and assess the nation’s available water resources at varying intervals since the late 1970s. The last water resource assessment research project was carried out in 1990. This old study addressed surface water availability assessments and used time series data which ended in 1989. To date the outputs of this 1990 project are at the centre of national and regional water resource planning. This research project, which is commonly referred to as WR2005 is the best attempt to capture the latest available water assessment techniques, improved hydrological simulations, integrate water resource data which included data on groundwater, surface water, wetlands, water quality, soils, landuse, improved catchment delineation, population, return flows, and several other variables that have a bearing on the quantification and assessment of the available water resources.
The emphasis in this research project was to provide the best possible tools, data and information on South Africa’s national water resources. In addressing this main objectives, a consortium of seven research teams from seven consulting companies shared project work tasks on the basis of how each team was already working with the Department of Water Affairs and Forestry to ensure that the project teams build on their strengths from past water assessment studies. In this project several models were developed to simulate and evaluate various processes and scenarios which are components of the overall output of a national water assessment.
In this research the WRSM2000 model was redeveloped to include groundwater, better account for water quality and incorporate Streamflow reduction routines. A network Builder/ Visualiser for simulated catchments was developed as part of WR20005. A GIS framework was used as a shell for the models and data used in the assessment. Five user manuals for the models were produced and incorporated within the dynamic electronic framework. Meta data for the project data was captured, checked by stakeholders and added to the project models. The models in the WR2005 framework were simulated for each catchment and the outputs captured and processed to generate the water availability in each catchment. The parameters used in the new models, the data, simulation results and the GIS representation of the catchments and simulation results were documented for the use of the broader water resources stakeholders.
Application of the project output has already started in current catchment yield assessments and water resource planning scenarios for the Department of Water affairs and Forestry. The online DWAF Water management User forum database has also been updated with the data and simulation results from this project.